Apply to be a TradeMaster!
Filter menu expanded

Filters

469 items
Reset

SORT

Product Availability

Show In Stock Only (181)

Product Type

Accessory (1)
Adapter (1)
Air Flow Switch (2)
Air Meter (1)
Anemometer (1)
Aspirator Bulb (1)
Carrying Case (2)
Controller (16)
Flange (1)
Float Switch (8)

Switch

DPDT (1)
DPDT (Optional) (1)
DPST (1)
SPDT (62)
SPST (2)

Price Range

Under $1 (1)
$1 to $5 (1)
$5 to $10 (4)
$10 to $15 (4)
$15 to $20 (3)
$20 to $25 (11)
$25 to $30 (7)
$30 to $35 (7)
$35 to $40 (13)
$40 to $45 (3)

Dwyer

Help Face
Need a little help?
469 items
Grid
List
Compare
Product Image of 3/4" NPT Multi-Jet Brass Water Meter, Max. 30 GPM
3/4" NPT Multi-Jet Brass Water Meter, Max. 30 GPM
SKU: WM2-A-C-03
Dwyer
SKU: WM2-A-C-03
Brand: Dwyer
(1)
$167.53 each
In Stock
Get 23 by Tomorrow, Aug 19
In Stock
Get 23 by Tomorrow, Aug 19
Compare
Product Image of 1" NPT Paddle Flow Switch
1" NPT Paddle Flow Switch
SKU: FS-2
Dwyer
SKU: FS-2
Brand: Dwyer
(1)
$93.73 each
In Stock
Get 9 by Tomorrow, Aug 19
In Stock
Get 9 by Tomorrow, Aug 19
Compare
Product Image of Flotect Mini-Size Brass Flow Switch, Normally Open or Closed
$96.63 each
In Stock
Get 9 by Tomorrow, Aug 19
In Stock
Get 9 by Tomorrow, Aug 19
Compare
Product Image of Adjustable Differential Pressure Switch w/ M20 Connection (.20" - 2.0" W.C.)
$37.47 each
In Stock
Get 52 by Tomorrow, Aug 19
In Stock
Get 52 by Tomorrow, Aug 19
Compare
Product Image of 4" Hook Style SS Static Pressure Tip w/ Mounting Flange
$20.69 each
In Stock
Get 20 by Tomorrow, Aug 19
In Stock
Get 20 by Tomorrow, Aug 19
Compare
Product Image of Red Outdoor Static Pressure Sensor w/ 50' Vinyl Tubing
$103.23 each
In Stock
Get 7 by Tomorrow, Aug 19
In Stock
Get 7 by Tomorrow, Aug 19
Compare
Product Image of 4" Straight Stainless Steel Static Pressure Tip w/ Mounting Flange
$8.86 each
Out of Stock
Get it by Wed, Sep 2 - Thu, Sep 10
Out of Stock
Get it by Wed, Sep 2 - Thu, Sep 10
Compare
Product Image of Adjustable Differential Pressure Switch w/ M20 Connection (.12" - 1.6" W.C.)
$38.54 each
In Stock
Get 1 by Tomorrow, Aug 19
In Stock
Get 1 by Tomorrow, Aug 19
Compare
Product Image of Wet/Wet Differential SPDT Pressure Switch, 1/4" FNPT, NEMA 4X (2.5 - 10 PSI)
$136.76 each
In Stock
Get 10 by Tomorrow, Aug 19
In Stock
Get 10 by Tomorrow, Aug 19
Compare
Product Image of Compact Low Differential Pressure Switch (.07" - .15" W.C.)
$86.27 each
In Stock
Get 2 by Tomorrow, Aug 19
In Stock
Get 2 by Tomorrow, Aug 19
Compare
Product Image of Adjustable Differential Pressure Switch w/ 1/2" NPT Connection (.08" - 1.20" W.C.)
$45.48 each
In Stock
Get 18 by Tomorrow, Aug 19
In Stock
Get 18 by Tomorrow, Aug 19
Compare
Product Image of 3/16" ID Rubber Latex Tubing 9'
3/16" ID Rubber Latex Tubing 9'
SKU: A-201
Dwyer
SKU: A-201
Brand: Dwyer
$19.67 each
In Stock
Get 1 by Thu, Aug 20
In Stock
Get 1 by Thu, Aug 20
Compare
Product Image of Adjustable Differential Pressure Switch w/ M20 Connection (.08" - 1.20" W.C.)
$30.32 each
In Stock
Get 24 by Tomorrow, Aug 19
In Stock
Get 24 by Tomorrow, Aug 19
Compare
Product Image of 2000 Series Differential Pressure Gauge (0 - 2" W.C.)
$84.45 each
In Stock
Get 3 by Tomorrow, Aug 19
In Stock
Get 3 by Tomorrow, Aug 19
Compare
Product Image of 2/20GPM 1" Flowmeter, SS Float
2/20GPM 1" Flowmeter, SS Float
SKU: LFME-13-F2
Dwyer
SKU: LFME-13-F2
Brand: Dwyer
$265.37 each
In Stock
Get 9 by Tomorrow, Aug 19
In Stock
Get 9 by Tomorrow, Aug 19
Compare
Product Image of Installer Kit w/ 2 Static Pressure Tips & PVC Tubing
$16.36 each
In Stock
Get 5 by Tomorrow, Aug 19
In Stock
Get 5 by Tomorrow, Aug 19
Compare
Product Image of Liquid Manometer, Red Fluid (0 - 3" W.C.)
Liquid Manometer, Red Fluid (0 - 3" W.C.)
SKU: MARK-II-25
Dwyer
SKU: MARK-II-25
Brand: Dwyer
$60.70 each
In Stock
Get 5 by Tomorrow, Aug 19
In Stock
Get 5 by Tomorrow, Aug 19
Compare
Product Image of Static Pressure Pickup Plate
Static Pressure Pickup Plate
SKU: A-417A
Dwyer
SKU: A-417A
Brand: Dwyer
$23.53 each
In Stock
Get 4 by Tomorrow, Aug 19
In Stock
Get 4 by Tomorrow, Aug 19
Compare
Product Image of Current/Voltage Signal Generator
Current/Voltage Signal Generator
SKU: CSG
Dwyer
SKU: CSG
Brand: Dwyer
(2)
$310.24 each
In Stock
Get 7 by Tomorrow, Aug 19
In Stock
Get 7 by Tomorrow, Aug 19
Compare
Product Image of 3/4" Midwest Bronze Sight Flow Indicator
3/4" Midwest Bronze Sight Flow Indicator
SKU: SFI-100-3/4
Dwyer
SKU: SFI-100-3/4
Brand: Dwyer
$274.61 each
In Stock
Get 3 by Tomorrow, Aug 19
In Stock
Get 3 by Tomorrow, Aug 19
Compare
Product Image of Water Leak Detector, DPDT Relay w/ Adjustable Mounting Bracket (24VAC/11-27VDC)
$70.63 each
Out of Stock
Get it by Wed, Sep 2 - Thu, Sep 10
Out of Stock
Get it by Wed, Sep 2 - Thu, Sep 10
Compare
Product Image of Differential Pressure Switch w/ Manual Reset (1.4" - 5.5" W.C.)
$132.10 each
In Stock
Get 6 by Tomorrow, Aug 19
In Stock
Get 6 by Tomorrow, Aug 19
Compare
Product Image of Magnehelic Differential Pressure Gage (0 - 1.0" W.C.)
$115.09 each
In Stock
Get 8 by Tomorrow, Aug 19
In Stock
Get 8 by Tomorrow, Aug 19
Compare
Product Image of Steel Mounting Bracket for Magnehelic Gages
$76.82 each
In Stock
Get 6 by Tomorrow, Aug 19
In Stock
Get 6 by Tomorrow, Aug 19
Compare
Product Image of Water Pump Pressure Switch, Normally Open (15 - 80 PSIG)
$23.85 each
In Stock
Get 3 by Thu, Aug 20
In Stock
Get 3 by Thu, Aug 20
Compare
Product Image of Compact Low Differential Pressure Switch (.15" - .5" W.C.)
$73.19 each
In Stock
Get 5 by Tomorrow, Aug 19
In Stock
Get 5 by Tomorrow, Aug 19
Compare
Product Image of Wet/Wet Differential SPDT Pressure Switch, 1/4" FNPT, NEMA 4X (10 - 25 PSI)
$142.03 each
In Stock
Get 5 by Tomorrow, Aug 19
In Stock
Get 5 by Tomorrow, Aug 19
Compare
Product Image of SPDT Digital Farenheit Temperature Switch (110V)
$72.98 each
In Stock
Get 3 by Tomorrow, Aug 19
In Stock
Get 3 by Tomorrow, Aug 19
Compare
Product Image of Plastic Carrying Case w/ 3/16" ID x 9' Rubber Tubing for Magnehelic Gages
$124.65 each
In Stock
Get 2 by Tomorrow, Aug 19
In Stock
Get 2 by Tomorrow, Aug 19
Compare
Product Image of 8" Straight Stainless Steel Static Pressure Tip w/ Mounting Flange
$12.68 each
In Stock
Get 12 by Thu, Aug 20
In Stock
Get 12 by Thu, Aug 20
Compare
Product Image of Flush Mount Space Pressure Sensor
Flush Mount Space Pressure Sensor
SKU: A-465
Dwyer
SKU: A-465
Brand: Dwyer
$40.00 each
In Stock
Get 12 by Thu, Aug 20
In Stock
Get 12 by Thu, Aug 20
Compare
Product Image of Compact Low Differential Pressure Switch (0.40" - 1.6" W.C.)
$70.65 each
In Stock
Get 2 by Tomorrow, Aug 19
In Stock
Get 2 by Tomorrow, Aug 19
Compare
Product Image of Magnehelic Differential Pressure Gage (0 - .25" W.C.)
$129.74 each
In Stock
Get 3 by Tomorrow, Aug 19
In Stock
Get 3 by Tomorrow, Aug 19
Compare
Product Image of Humidity/Temperature Sensor Transmitter, 2% OSA 4-20 mA
Humidity/Temperature Sensor Transmitter, 2% OSA 4-20 mA
SKU: RHPX-2SSAB-00
Dwyer
SKU: RHPX-2SSAB-00
Brand: Dwyer
$189.41 each
In Stock
Get 4 by Tomorrow, Aug 19
In Stock
Get 4 by Tomorrow, Aug 19
Compare
Product Image of Flotect Liquid Level Switch
$229.99 each
In Stock
Get 1 by Tomorrow, Aug 19
In Stock
Get 1 by Tomorrow, Aug 19
Compare
Product Image of Magnehelic Differential Pressure Gage (0 - 3.0" W.C.)
Magnehelic Differential Pressure Gage (0 - 3.0" W.C.)
SKU: 2003-DWYER
Dwyer
SKU: 2003-DWYER
Brand: Dwyer
(1)
$104.66 each
In Stock
Get 9 by Tomorrow, Aug 19
In Stock
Get 9 by Tomorrow, Aug 19
Compare
Product Image of Single Stage Weatherproof Digital Temperature Switch, 90 to 255 VAC w/ Probe
$134.51 each
In Stock
Get 1 by Fri, Aug 21
In Stock
Get 1 by Fri, Aug 21
Compare
Product Image of Thermocouple Farenheit Temperature Switch, J/K/S Input (115V)
$98.78 each
In Stock
Get 3 by Tomorrow, Aug 19
In Stock
Get 3 by Tomorrow, Aug 19
Compare
Product Image of 2000 Series Differential Pressure Gauge (0 - 5" W.C.)
$88.34 each
In Stock
Get 6 by Tomorrow, Aug 19
In Stock
Get 6 by Tomorrow, Aug 19
Compare
Product Image of SPDT Boiler Water Level Control, Snap Switch
SPDT Boiler Water Level Control, Snap Switch
SKU: 123-7000-153
Dwyer
SKU: 123-7000-153
Brand: Dwyer
$791.23 each
In Stock
Get 11 by Tomorrow, Aug 19
In Stock
Get 11 by Tomorrow, Aug 19
Compare
Product Image of Compact Low Differential Pressure Switch (3.0" - 11.75" W.C.)
$92.56 each
In Stock
Get 8 by Tomorrow, Aug 19
In Stock
Get 8 by Tomorrow, Aug 19
Compare
Product Image of MS Magnasense Differential Pressure Transmitter w/ LCD, 4-20 mA
$175.24 each
In Stock
Get 3 by Tomorrow, Aug 19
In Stock
Get 3 by Tomorrow, Aug 19
Compare
Product Image of Compact Low Differential Pressure Switch (1.40" - 5.5" W.C.)
$91.23 each
In Stock
Get 1 by Tomorrow, Aug 19
In Stock
Get 1 by Tomorrow, Aug 19
Compare
Product Image of Single Stage Weatherproof Digital Temperature Switch, 12 to 24 VAC/VDC, w/ Probe
$117.51 each
In Stock
Get 2 by Thu, Aug 20
In Stock
Get 2 by Thu, Aug 20
Compare
Product Image of Brass Bourdon Tube SPDT Pressure Switch w/ Snap Action Switch & Adj. Deadband (10 - 300 PSIG)
$1,030.02 each
In Stock
Get 1 by Tomorrow, Aug 19
In Stock
Get 1 by Tomorrow, Aug 19
Compare
Product Image of Adjustable Differential Pressure Switch w/ 1/2" NPT Connection (.20" - 2.0" W.C.)
$37.94 each
In Stock
Get 12 by Tomorrow, Aug 19
In Stock
Get 12 by Tomorrow, Aug 19
Compare
Product Image of Thermocouple Limit Control, Farenheit, Type J/K/S Input (110V)
$156.27 each
In Stock
Get 1 by Tomorrow, Aug 19
In Stock
Get 1 by Tomorrow, Aug 19
Compare
Product Image of Adjustable Air Flow Paddle Switch w/ Stainless Steel Vane (200-1800 FPM)
Adjustable Air Flow Paddle Switch w/ Stainless Steel Vane (200-1800 FPM)
SKU: AAFS
Dwyer
SKU: AAFS
Brand: Dwyer
$111.82 each
In Stock
Get 4 by Thu, Aug 20
In Stock
Get 4 by Thu, Aug 20
Resources
FAQs, Manuals & Videos
Articles
More About Dwyer

Dwyer Instruments traces its roots to 1931, when the F.W. Dwyer Manufacturing Company was founded in Chicago to produce liquid filled manometer test instruments. In 1953 the company developed the Magnehelic gauge, which grew into its flagship product and helped drive the company's expansion.

As the business grew, Dwyer moved its headquarters from Chicago to Michigan City, Indiana, where it remains today, with additional offices supporting customers across Asia, Europe, and Australia. The company now manufactures instrumentation for HVAC and process automation markets.

Product Lines

Dwyer's pressure product line includes the Series 2000 Magnehelic differential pressure gauges and Series MSX Magnesense differential pressure transmitters, both used to measure low air or non-corrosive gas pressure. The catalog also covers manometers, flow meters, flow switches, and flow indicators for measuring flow rate in liquids and gases.

Beyond pressure and flow, Dwyer supplies controllers, data loggers, remote displays, and sensors for temperature, level, and air velocity, along with calibration services and accessories for the instruments it manufactures.

Why Contractors Specify Dwyer

Magnehelic gauges have been used in the field since the 1950s for tasks like filter monitoring, duct static pressure checks, and cleanroom pressure differential readings, giving contractors a design with a long track record. Because the gauge uses a frictionless internal movement, it reads pressure without external power.

Carrying pressure, flow, level, and temperature instruments under a single brand simplifies sourcing replacement parts and matching new installations to existing equipment already in the field. That range makes Dwyer instruments a common choice for HVAC balancing, air quality monitoring, and process control work.

How to Choose Dwyer Products

Begin with what needs to be measured: pressure, flow, level, or temperature, since Dwyer's product lines are organized around these measurement types. For pressure applications, decide between a mechanical gauge like the Series 2000 Magnehelic for local visual readings or a transmitter like the Series MSX Magnesense when a signal needs to reach a building automation or control system.

Check the pressure range, accuracy, and gas compatibility required for the application, and confirm whether the instrument will be exposed to corrosive gases before selecting a model. Mounting location and available power at the install point should also factor into the choice between a gauge and a transmitter.

Frequently Asked Questions

What is a Magnehelic gauge used for?

It measures low differential air or non-corrosive gas pressure, whether positive, negative, or differential, and is commonly used for filter monitoring, duct static pressure, and cleanroom pressure differential readings.

What is the difference between the Series 2000 Magnehelic gauge and the Series MSX Magnesense transmitter?

The Series 2000 is a mechanical dial gauge for local visual reading, while the Series MSX is an electronic transmitter that sends a signal to a building automation or control system.

Does a Magnehelic gauge need external power?

No, the Magnehelic gauge uses a frictionless internal movement and does not require external power to operate.

Where is Dwyer Instruments headquartered?

Dwyer is headquartered in Michigan City, Indiana, with additional offices in Asia, Europe, and Australia.

What industries rely on Dwyer instrumentation?

Dwyer instruments are used in HVAC and process automation applications, including air quality, flow, level, temperature, and process control monitoring.